Vodafone Group, the mobile telecoms company, is preparing to increase its stake in Vodacom, South Africa’s largest mobile operator, to 50 per cent at a cost of £1.35 billion.

Vodafone today said it has entered exclusive talks with the Rembrandt Trust, the South Africa-based investment company, to buy its stake in VenFin, a holding vehicle that owns a 15 per cent stake in Vodacom. Vodafone already owns 35 percent of Vodacom.

The British group said that an increased interest in Vodacom "was consistent with Vodafone’s strategy of increasing its exposure to growth markets".

A successful deal would give Vodafone joint control of Vodacom with Telkom, South Africa’s fixed-line carrier.

Vodacom has 17.2 million mobile phone subscribers in South Africa, Mozambique, the Democratic Republic of Congo, Tanzania and Lesotho.

The deal follows acquisitions by Vodafone in the Indian, Czech and Romanian markets this year as part of its strategy to boost its exposure in under-penetrated, high-growth emerging markets.

South African mobile penetration is around 57 per cent compared to 100 per cent in some European markets and mobile use across the African continent is growing rapidly due to a lack of fixed-line telecoms infrastructure and the increasing availability of very cheap mobile handsets.

Vodafone shares were 1p higher at 150.5p in morning deals in London. To track the stock click here.

The mobile phone retailer and telecoms provider said pre-tax profits were up to £37 million on turnover up 25 per cent at £1.29 billion in the 26 weeks to October 1.

The company also unveiled plans for a major push into the UK broadband market next year through the unbundling of up to 1,000 telephone exchanges. The move would involve putting Carphone equipment into BT exchanges so it can control the line to the home and offer a range of telecoms services, such as phone lines and internet access.

Charles Dunstone, the chief executive, said: "The outlook continues to be positive. We expect the mobile phone market to continue to grow year-on-year over the Christmas period and into New Year, with our own prospects underpinned by our store opening programme and a very strong product portfolio."

He added: "Our strong commitment to the UK broadband market further builds on our foundations to become the clear number one alternative telecoms provider."

Shares in Carphone Warehouse gained 5.75p at 204.25p in early afternoon trade. To track the stock click here.

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